DPM system protection CPU load on target

Question

We're backing up 2 virtual domain controllers via system state backup. This is working fine, but something changed at the beginning of May, because since then both VMs are under much larger CPU load during the system state backup.
Before the CPU load was 40% at most, since May, it's 90%. There was no hardware change in the VMs' config, the only change are the regular Windows updates and UR on DPM 2019.

Any idea why this might be happening/what's causing it?

What I've tried:

• move the VMs to different Hyper-V hosts
• delete the backups in DPM and recreate them
• backup the system state on different DPM server

Nothing of the above helped, the behavior is always the same.

Here's sample CPU load graph from this year:

Answer 1

Noone has encountered problem like this?